A 38-year study of Californians, begun by the American Cancer Society and concluded by the University of California at Los Angeles (UCLA), has concluded that secondhand smoke has little if any negative impact on mortality.

The study, published in the May 17 issue of the British Medical Journal, throws cold water on the efforts of state and local governments to ban smoking in restaurants and other public places in the name of public health.

100,000 Californians Studied

From 1959 through 1998, the American Cancer Society tracked a broad cross-section of more than 100,000 Californians, dividing the study participants according to whether or not they were married to smokers. Researchers also monitored participants’ exposure to other sources of environmental tobacco smoke.

In 1999, UCLA epidemiologist James Enstrom and State University of New York epidemiologist Geoffrey Kabat began analyzing the American Cancer Society data. According to their study, “No significant associations were found for current or former exposure to environmental tobacco smoke.

“The results do not support a causal relation between environmental tobacco smoke and tobacco related mortality, although they do not rule out a small effect,” Enstrom and Kabat write. “The association between tobacco smoke and coronary heart disease and lung cancer may be considerably weaker than generally believed.”

Most Studies Reach Similar Conclusions

“Since anti-smoking activists and public health officials confidently assert annual death tolls from secondhand smoke of 50,000 or more, you may suspect that Dr. Enstrom and Dr. Kabat’s findings are unusual,” noted Jacob Sullum in the Washington Times.

“They are in fact similar to the results of most studies looking for a connection between ETS and lung cancer or heart disease. Such research typically finds small, statistically insignificant associations.”

“The study’s findings are consistent with those of the [Centers for Disease Control] and other epidemiological [environmental tobacco smoke] research,” said Kimberly Bowman of the American Council on Science and Health.

She continued, “Ultimately, the study does not exonerate tobacco companies, but it strikes a blow at the public’s misperception of the ill effects of secondhand smoke--and does so shortly after New York City Mayor Michael Bloomberg’s creation of a ban on smoking in restaurants and bars, based largely on purportedly life-threatening health hazards to employees. The study suggests that the public’s fears--and politicians’ ideas--about how we are affected by [environmental tobacco smoke] may be misguided.”

Notably, Enstrom and Kabat’s work confirmed that smoking is harmful to the health of the smoker. However, the harmful health effects do not extend to persons exposed only to secondhand smoke.

“It is generally considered that exposure to environmental tobacco smoke is roughly equivalent to smoking one cigarette per day,” states the study. “If so, a small increase in lung cancer is possible, but the commonly reported 30 percent increase in heart disease risk--the purported cause of almost all the deaths attributed to secondhand smoke--is highly implausible.”

Nicotine May Delay Alzheimer’s

A separate study, published in the online edition of the Proceedings of the National Academy of Sciences, has linked a nicotine byproduct with a delay in the onset of Alzheimer’s disease.

Dr. Kim Janda, a professor of chemistry at the Scripps Research Institute in La Jolla, California, and his colleague Tobin Dickerson report that a byproduct of nicotine metabolism may prevent the formation of brain-clogging plaques that have been linked to Alzheimer’s.

The study supports previous research that uncovered a link between smoking and a delay in the onset of Alzheimer’s.

Although the results are not yet conclusive, the mounting evidence linking nicotine and Alzheimer’s prevention may enable scientists to create a drug that can help prevent the onset of Alzheimer’s. Currently, 4 million Americans have the disease, which is characterized by chronic disorientation and memory loss.

The article, “Glycation of the amyloid beta-protein by a nicotine metabolite: A potentially fortuitous chemical dynamic between smoking and Alzheimer’s disease,” appears in the 6/16/2003-6/20/2003 online edition of the journal Proceedings of the National Academy of Sciences. the week of 6/16/2003 to 6/20/2003. The article will appear in print later this year.

“Glycation of the amyloid beta-protein by a nicotine metabolite: A potentially fortuitous chemical dynamic between smoking and Alzheimer’s disease,” authored by Dr. Kim Janda and Tobin Dickerson and published in the 6/16/2003-6/20/2003 online edition of the journal Proceedings of the National Academy of Sciences, is available online at http://www.pnas.org/cgi/doi/10.1073/pnas.1332847100.